1. Field of the Invention
The present invention relates to a process for the removal of organic or inorganic pollutants from water, and particularly to a method for removing organic dyes from wastewater by using magnetic polymer microspheres.
2. Description of the Related Art
Water pollution is the introduction of physical, chemical and biological substances into bodies of water that spoils the purity of water, which ultimately causes hazardous effects on living species, including those that consume the water. Water pollution is a very persistent problem, and the intensive disposal of different toxic substances without control constitutes a real danger. Wastewater from the manufacture of textiles, cosmetics, printing, dyeing, food coloring, paper making, etc., is often polluted by dyes. It has been estimated that about 1-15% of dyes are lost during the dyeing process in the textile industry and are eventually released as wastewater. These colored effluents pollute both surface water and the ground water system. Many dyes and pigments are toxic carcinogens and produce mutagenic effects. Organic dyes, such as Congo red, methyl blue, methylene blue, malachite green, rhodamine B, bromophenol blue. and rose Bengal dyes, are toxic and may cause cancer and other health side effects for both humans and aquatic life.
Dyes, when discharged into receiving streams, will generally cause detrimental effects on the liver, gill, kidney, intestine, gonads and pituitary gonadotrophic cells of aquatic life. In humans, they may cause irritation to the respiratory tract if inhaled, and irritation to the gastrointestinal tract if ingested. Contact of the dyes with skin and eyes may cause irritation with redness and permanent injury in other cases. The toxicity of Congo Red, Malachite Green, Rhodamine B, bromophenol blue, and Rose Bengal dyes to humans includes carcinogenicity, reproductive and developmental toxicity, neurotoxicity, and acute toxicity.
Alternatives have been contemplated for decontaminating waters, such as extraction with solvents, reverse osmosis, absorption on zeolites and absorption on activated carbon. As dyes in wastewater cannot be efficiently decolorized by traditional methods, the adsorption of synthetic dyes on inexpensive and efficient solid supports was considered as a simple and economical method for their removal from water and wastewater. The adsorption characteristics of a wide variety of inorganic and organic supports and size, such as micro- or nano-adsorbents, have been measured, and their capacity to remove synthetic dyes has been evaluated. Recently, various nano-adsorbents composed of polymers, inorganic materials or carbon have been developed for separating these stable, recalcitrant, colorant, and potentially carcinogenic dyes. Despite achieving efficiency in removing organic dyes, these nano-adsorbents have been found to be greatly limited in scope because these materials for treating wastewater require an additional separation step to remove the adsorbent from the solution.
Thus, a method for removing organic dye from wastewater solving the aforementioned problems is desired.